The CSS syntax is made up from three parts:  selector, property and value:

selector {property: value}

body {color: #ffffff}

• The selector is normally the HTML element/tag you wish to define, like body
• The property is the attribute you wish to change like color, and font
• The value is the property value: #ffffff

HTML class tag

If you want to have paragraph (tag p) with right-aligned. You can write it like this:

<p class="right">
Right-aligned.
</p>

p.right {text-align: right}

You can also omit the tag name in the selector to define a style that will be used by all HTML elements that have a certain class. In the example below, all HTML elements with class=”right” will be right-aligned:

.right{text-align: right}

HTML ID tag

You can also define styles for HTML elements with the id selector. The id selector is defined as a # in css. 

<p id="right">
Right-aligned.
</p>